Automatic sliding doors are used in commercial and non-commercial settings in order to allow people and things to enter and exit a given area without having to open and close the door manually. Automatic sliding doors are subject to almost constant use, particularly in commercial and industrial buildings. As a result, repair and maintenance of these doors is costly. In commercial settings, for example, DIY (do it yourself) stores, automatic doors and their guide tracks located on the floor at the threshold of the door are subject to significant wear and damage due to high levels of consumer traffic and the movement of machinery such as forklifts, hand trucks, and pallet movers through the door. In addition, these doors are also exposed to large amounts of debris which can interfere with the sliding operation of the door. This debris may range in size from very small particles (e.g., sand, top soil) to larger objects (e.g., gravel, screws, nuts, bolts, etc.). The guide track is also exposed to rainwater, snow, ice, ice melting agents and other debris from outside the building.
In commercial settings, automatic sliding doors must also be able to swing outward in the direction of egress to allow people to safely and quickly exit the building in case of an emergency. This feature also is necessary to comply with fire codes and other regulations. Typically, automatic sliding doors have a guide track set in the floor that allows the door panels to both slide and swing. To allow the door to swing, the lock area of the door disengages and the mechanism that travels along the guide track pivots when the door is subject to emergency egress.
Typically, floor guide systems consist of a pin guide assembly attached to the door that travels within a track along the floor, sometimes called a pin guide track. This pin guide track directs the sliding of the automatic door along a specified path. The pin guide assembly usually has a cross sectional shape that matches the cross sectional shape of the pin guide track. This fit ensures that the door slides along the desired path. A problem with known pin guide assemblies and pin guide track systems is that they are subject to damage when the pin guide assembly and/or the pin guide track area of the door is impacted from misuse of the door. For example, if the door is subject to impact in a manner that forces the pin guide assembly out of the pin guide track, such as impact at the heel of the door, the pin guide assembly, the pin guide track, or both may be damaged.
Another problem with known pin guide assemblies and pin guide tracks is that debris can fall into the slot of the pin guide track, jamming the track, preventing or inhibiting the pin guide assembly from moving along the pin guide track. Debris in the slot may also increase wear of the pin guide assembly and pin guide track, particularly when the debris consists of hard substances like sand.
Another problem with known pin and pin guide systems is that they can be adversely affected by misalignment. Because of variations in height of the floor beneath the pin guide, the elevation of the guide may vary with respect to the door as the pin slides along the guide. An uneven floor surface may also cause the pin guide track to twist, for example, because traffic through the door causes part of the threshold to be pushed down while other parts of the threshold outside the path of traffic flow are not pushed down. Uneven elevation and twisting of the pin guide track may also be caused by cracks that can form in the flooring and by uneven settling of the floor that can occur with newly constructed building. The problem of uneven and twisted pin guide tracks may also result when a door is installed by less experienced personnel. Misalignment of the pin guide track may cause uneven wear of the pin guide assembly and the pin guide track or may damage the pin guide assembly as it travels along the pin guide track or cause door system to rub and damage the finish of the door. Misalignment may also cause the pin guide assembly to jam in the pin guide track preventing movement of the door.